themes/robbyrussell: Add Python Virtual environment indicator (#536)

Co-authored-by: programmer <programmer@debian.debian>

themes/robbyrussell/robbyrussell.theme.sh

@@ -3,24 +3,39 @@
 # This theme attempts to replicate the default "robbyrussell" theme from ohmyzsh:
 #  https://github.com/ohmyzsh/ohmyzsh/blob/master/themes/robbyrussell.zsh-theme
 
+# Example outside git repo:
+# ➜  ~
+# Example inside clean git repo:
+# ➜  config-files git:(main)
+# Example inside dirty git repo:
+# ➜  config-files git:(main ?:1) ✗
+# Example with virtual environment:
+# ➜  (env1) ~
+# Example with virtual environment and inside git repo:
+# ➜  (env1) config-files git:(main)
+# python_venv setup
+OMB_PROMPT_VIRTUALENV_FORMAT='(%s) '
+OMB_PROMPT_SHOW_PYTHON_VENV=${OMB_PROMPT_SHOW_PYTHON_VENV:=true}
+
 function _omb_theme_PROMPT_COMMAND() {
     if [[ "$?" == 0 ]]; then
         local arrow_color="${_omb_prompt_bold_green}"
     else
         local arrow_color="${_omb_prompt_bold_brown}"
     fi
-
+    # set the python_venv format
+    local python_venv; _omb_prompt_get_python_venv
+    python_venv="$_omb_prompt_olive$python_venv"
     local base_directory="${_omb_prompt_bold_teal}\W${_omb_prompt_reset_color}"
     local GIT_THEME_PROMPT_PREFIX="${_omb_prompt_bold_navy}git:(${_omb_prompt_bold_brown}"
     local SVN_THEME_PROMPT_PREFIX="${_omb_prompt_bold_navy}svn:(${_omb_prompt_bold_brown}"
     local HG_THEME_PROMPT_PREFIX="${_omb_prompt_bold_navy}hg:(${_omb_prompt_bold_brown}"
     local SCM_THEME_PROMPT_SUFFIX="${_omb_prompt_reset_color}"
     local SCM_THEME_PROMPT_CLEAN="${_omb_prompt_bold_navy})${_omb_prompt_reset_color}"
     local SCM_THEME_PROMPT_DIRTY="${_omb_prompt_bold_navy}) ${_omb_prompt_olive}✗${_omb_prompt_reset_color}"
-
     local arrow="${arrow_color}➜${_omb_prompt_reset_color}"
 
-    PS1="${arrow}  ${base_directory} "
+    PS1="${arrow}  ${python_venv}${base_directory} "
 
     local scm_info=$(scm_prompt_info)